Phil,
I agree that the robber barons usually get short shrift in the bastardized histories we get today.
However, many of them were against true competition and for cartels (circa 1880-1900) which they tried to form by secret cartel agreements and mega-mergers (e.g., U.S. Steel) in order to cut production and raise prices. During that period, prices were generally falling because of increases in productivity.
These cartels or monopolies didn't work in the free market because one of the cartel members would cheat and work to their own advantage, or some upstart new company would form to take advantage of the opportunity presented by the prices being so much higher than costs.
So, they turned to the government in the "progressive" era (circa 1900-1917) to enforce these monopolies. It's how we got so many of the federal commissions such as the ICC, FTC, FCC, and even the Fed. (the banker's cartel, 1913). To bad the liberals can't see how one their favorite devices ("regulatory" agencies) led to the corporatist state we are in today where the little guy is really getting screwed.
So it seems that history has both sides wrong: the robber barons are vilified for producing things and making money fair and square, and no one says anything about their incestuous relationship with the government which restrict competitions and make it hard for new companies to enter 'established' markets.
Rich